Device in a circular knitting machine for controlling two lock-systems



May 8, 1962 3,033,013

- H. Luril AK DEVICE IN A CIRCULAR KNITTING MACHINE FOR CONTROLLING TWO LOCK-SYSTEMS Filed June 12, 1959 4 Sheets-Sheet 1 24 EiiF-IIN IN VEN TOR. IV, II I T WM May 8, 1962 H. LUN/A/K 3,033,013

DEVICE IN A CIRCULAR KNITTING MACHINE FOR CONTROLLING TWO LOCK-SYSTEMS Filed June 12, 1959 4 Sheets-Sheet 2 INVENTOR.

y 8, 1962 H. LUN/A/K 3,033,013

DEVICE IN A CIRCULAR KNITTING MACHINE FOR CONTROLLING TWO LOCK-SYSTEMS Filed June 12, 1959 4 Sheets-Sheet 3 IN V E]! TQR. W 0104 fun 44 y 8, 1962 H. LUNA K 3,033,013

DEVICE IN A CIRCULAR KNITTING MACHINE FOR CONTROLLING TWO LOCK-SYSTEMS Filed June 12, 1959 4 Sheets-Sheet 4 INVEN 14$; 94412044? United States Patent ()fiice 3,033,913 Patented May 8, 1962 Czechoslovakia Filed June 12, 1959, Ser. No. 819,882 2 Claims. (Cl. 66--41) The present invention relates to a device in .a circular knitting machine for controlling two cam-systems having different stroke ratios, and in particular to a device of the aforementioned type in a single-cylinder machine equipped with a circular dial and employing a single thrust rod and a single row of actuating drum cams on a main pattern drum.

Machines are known in which the upper end of the thrust rod directly controls the transfer bit operating cams by means of a horizontal two-arm lever. The cams control movement of the transfer bits during the formation of the setting-up course and transfer of the loops of the first course to cylinder needles, the different heights of the drum cams on the main pattern drum being directly proportional to the required strokes of said transfer bit cams.

On the other hand, the needle cams, which actuate the cylinder needles during formation of the setting-up course and during transfer and which have different stroke ratios corresponding to the heights of the cylinder needle butts, are controlled by the same thrust rod by means of a vertically disposed cam which is secured at a side of the rod and which, due to its particular shape, actuates a horizontally rotatable two-arm lever. One end of this lever is bevelled andslides along the cam on the thrust rod, and the other end of the lever charges the needle cams towards the needle cylinder.

The aforementioned control device has the disadvantage that friction of the lever on the thrust rod cam causes relatively rapid wear because of unfavorable stress distribution. The shape of the thrust rod cams must be precisely maintained, and even a very small deviation from the correct contour during manufacture results in an incorrect length of the cam stroke and breakdown in operation. The adjustment of the transmission mechanism is difiicult. Because of mechanical pressures and jamming of the transmission mechanism, the cam on the actuating rod is frequently loosened.

The present invention aims at removing the aforedescribed drawbacks of the hitherto known devices. It is an object of the invention to permit a change in the transmission ratios of the control device While it actuates the transfer cams and the needle cams of the needle cylinder, so as to adapt them to different and variable requirements as to the length of stroke of the tWo cam systems.

According to the main feature of the invention .a transmission member, such as a bell crank-lever is provided, the transmission ratio of which varies with the change in length of one of its arms during the stroke of the cooperating thrust rod of the main pattern drum as a function of the position of said lever. The shorter .arm of the bell crank lever, which is pivotally mounted for rocking movement on a supporting member, is provided with an abutment, such as a pin with a rounded head, and the longer arm carries two adjustable contact members such as screws at diiferent distances from the fulcrum of the lever. The operative end of the shorter arm of the bell crank lever contacts a horizontal lever which actuates radial displacement of the needle cams towards the needle cylinder, Whereas the contact members on the longer arm abut alternatingly against a stop secured to the thrust rod which directly actuates vertical displacement of the transfer cams towards the dial.

The accompanying drawings represent by way of example one embodiment of the present invention.

FIG. 1 is a plan view of the control mechanism,

FIG. 2 is a sectional view of a dial of the apparatus of FIG. 1 taken along the line a--a of FIG. 1 and an elevational view of associated elements in the direction of the arrow S of FIG. 1,

FIGS. 3 to 6 are elevational views of a detail of the apparatus of FIGS. 1 and 2 in various phases of operation, as seen in the direction of the arrow S of FIG. 1.

The device embodying the invention and shown in the drawings is mounted on a conventional single-cylinder circular knitting machine with a dial, of which but those parts are represented which have some bearing on the present invention.

The conventional knitting members are indicated in FIG. 1 by short butts 1 and long butts 2 of latch needles of a cylinder 3, and FIG. 2 shows transfer bits 4 with short butts 5 and long butts 6 in a dial 7. The butts 1 and 2 of the cylinder needles shown in FIG. 1 are acted upon either by a raising cam 8 or a lowering cam 9, the slides 10 and 11 of which are mounted for radial sliding movement in a guide 12 on a bracket 13 of a bed plate 14. The bed plate 14 is a part of the stationary knitting machine frame, not otherwise shown, on which all movable elements of the apparatus of the invention are supported.

The butts 5 and 6 (FIG. 2) of the transfer bits 4 are acted upon by a transfer cam 15 or by a transfer cam 16. The cams 15, 16, which are elements of the system of dial cams of the machine, are mechanically interconnected .and move in unison in a block 17. They are mounted for vertical displacement on a vertical pin 18 in a dial cap 19. An adjustable contact screw 21 provided in a horizontal two-arm lever 22, which is mounted for rocking movement on a pivot 23 in the bracket 13, abuts against an angle plate (FIG. 1) of the slide 11. The other end 24 of the lever 22 rests against a rounded head 25 of a pin 26 which is press-fitted in the shorter arm of a motion transmitting bell crank lever 27 mounted for rocking movement on a pivot 28 in a supporting plate 29 secured by screws 30 to the bracket 13. The pin 26, lever 22, contact screw 21, and angle plate 20 thus transmit motion from the lever 27 to the slide 11 and to the cam mounted thereon.

The longer arm of the lever 27 (FIG. 3) carries two adjustable contact screws 31, 32 which abuttingly engage a stop 33 which is secured by screws 34 to the vertical thrust rod 35. The stop 33 and the screws 31 and 32 constitute abutment means on the rod 35 and the lever 27 respectively, and jointly provide means for transmitting movement of the thrust rod to the lever. 33 has a flat horizontal abutment face. The lower bevelled end of the thrust rod 35 (FIG. 2) which is guided in the supporting plate 29 slides either on the surface of a main pattern drum 36 which is rotatable on the machine frame in the direction of the arrow (FIG. 2) or on cams 37, 38 which are placed in the same radial plane on the drum 36 behind one another. The low drum cam 37 precedes the high drum cam 38, which is provided with three steps or ramps 39, 40; 41 of different height. The upper horizontal end of the thrust rod 35 is aligned with an eccentric pin 42 of a two-arm actuating lever 43 which is mounted for rocking movement on a pivot 4-4 provided in the frame of the machine. The shorter arm 45 of the lever 43 cooperates with the block 17 of the transfer earns 15 and 16, and transmits the movement of the rod to the transfer cams.

The described device operates as follows:

When the device is at rest, the main pattern drum 36 The stop is in such a position that the lower end of the thrust rod 35 rests on the drum surface in front of the low drum cam 37 (FIG. 2). The upper end of the rod 35 assumes the position marked I in loose contact with the eccentric pin 42 of the lever 43. The short arm 45 of the lever 43 is out of reach of the block 17 which is in its upper terminal position marked II. Both transfer cams 15, 16 are in a posiiton above the long butts 6 of the transfer bits 4 and are inoperative. The bell crank lever 27 assumes a position marked I (FIG. 3) in which only the outer'set screw 31 rests against the bridge 33 of the thrust rod. The straight end 24 (FIG. 1) of the lever 22 contacts in the position I the head 25 of the pin 26 and both needle cams 8 and 9 are in the position I, out of contact with the long butts 2 of the needles of the cylinder 3, i.e. they are in their inoperative position.

When engagement of all needles has to take place, the main pattern drum is rotated in the direction of the arrow shown in FIG. 2 and the end of the thrust rod 35 strikes the low drum cam 37, whereby the rod 35 is raised. Its upper end assumes the position II in which the lever arm 45 touches block 17, but still-does not actuate the transfer cams 15, 16. The bell crank lever 27 assumes a position marked II (FIG. 4) in which again only the outer contact screw 31 rests on the stop 33 of the rod 35. The end 24 of the lever 22 swings around the pivot 23 from position I into a position II (FIG. 1) and causes the raising cam 8 to be displaced towards, but still out of range of the short butts 1 of the cylinder needles, so that the long butts 2 of the needles are elevattxi to such a height that the needles take yarn. When the end of the rod 35 drops from the low drum cam 37 (FIG. 2) onto the surface of the drum 36, the cam 8 returns into its inoperative position I.

Upon further rotation of the drum 36 in the direction of the arrow shown in FIG. 2, the end of the thrust rod 35 mounts the first step 39 of the high drum cam 33 so as to lift the rod 35. Its top end assumes a position III in which it actuates the pin 42 of the lever 43. The shorter arm 45 of the lever 43 pushes the block 17 to the position III in which both transfer earns 15, 16 are displaced half-way towards the short butts of the transfer bits 4 which are not influenced. The actuation of the cam (FIG. 1) produces a radial outward movement of the long butts 6 (FIG. 2) of the transfer'bits 4, and they are then returned to their original position by the action of the cam 16. The lever 27 assumes a position III (FIG. 5) in which the outer screw 31 still abuts against the stop 33 of the thrust rod 35. When the position III has been reached, the inner screw 32 is also in contact with the stop 33. Due to the simultaneous rocking movement of the lever 22 (FIG. 1) on the pivot 23 to the position III, the lowering cam 9 is pushed halfway toward the cylinder 3 into the position III so that it does not influence the short butts 1. In the position III of the block 17 and lever 27 (FIG. 5) both contact screws 31, 32 should abut against the stop 33 of the rod 35. A very simple adjustment of the cams 8, 9, 15, 16 just outside the respective contact screws 21, 31, and 32 for simultaneously positioning the range of the short butts 1, (FIG. 1) of the needles and 5 of the transfer bits 4 (FIG. 2), while the rod 35 is in position III, wili reliably synchronize the control device.

Prior to the transfer of loops from the transfer 'bits 4 to the needles the drum 36 revolves in the direction of the arrow shown in FIG. 2 to a further stage, in which the end of the rod 35 mounts the second and highest step 40 of the high drum cam 38.v The ensuing lifting movement of the rod 35 to the position IV causes the transfer cams 15, 16 to be completely inserted so that they act both on the long and the short butts of the transfer bits 4.

The bridge stop 33 now acts on the inner screw 32 of the lever 27, which assumes the position IV (FIG. 6). Since the inner screw 32 is much nearer the pivot 23 than the outer screw 31, the angular displacement of the shorter arm of the lever 27 relative to the movement of the stop 33 is greatly increased. Thisghanged transmission ratio corresponds to the r'quir l-g'reater displacement of the lowering cam 9 when the rod 35 moves from position III to position IV. The rocking movement of the lever 22 on the pivot 23 into the position IV (FIG. 1) produces the finaldisplacement of the lowering cam 9 through a distance corresponding to the length of the short butts 1 of the needles towards the cylinder 3. The transfer of the loops from the bits to thecylinder needles is terminated by further stages of operation of the drum 36 (FIG. 2) when the end of the thrust rod 35 slides from the second step 40 over the third step 41 to the surface of the drum 36, whereby all cams 8, 9, 15, 16 are permitted to return to their initial positions.

The displacement of the transfer cams 15, 16 towards the short butts 5 of the transfer bits 4, that is, from the position II to the position III according to FIG. 2,, is relatively large, whereas the displacement of the lowering cam 9 from the position II to the position 111 towards the short butts 1 of the cylinder needles is on the contrary short (FIG. 1). For this reason, the longer arm of the transmission lever 27 which is determined by the abutment of the outer set screw Cal-against the bridge 33 is sufficient, because it imparts to the shorter arm of the lever 27 the required smaller amplitude (FIG. 5).

On the other hand, the final shift of the transfer cam 15, 16 corresponding to the length of the short butts 5, that is, from the position III to the position IV according to FIG. 2, is relatively small, whereas the final shift of the lowering cam 9, correspondiugto the length of the short butts 1 of the needles, that is, from position 111 to position IV adjacent the needle cylinder 3 is large (FIG. 1). This is why shortening the arm of the transmission lever 27 is necessary, said arm being determined by the abutment of the inner contact screw 32 against the stop 33. It imparts to the lever 27 the required greater angular displacement (FIG. 6).

I claim:

1. In a knitting machine, in combination, a frame; a needle cam and a dial cam movable on said frame; a pattern drum rotatable on said frame; a thrust rod movable between a plurality of positions responsive to rotation of said drum; an abutment member on said rod; a lever mounted on said frame and rotatable about an axis; two contact members radially spaced on said lever, said abutment member and said contact members being arranged for transmitting movement of said abutment member to one of said contact members when said rod moves from a first to a second position, and to the other one of said contact members when said rod moves from said second toward a third position thereof; and means for operatively connecting said cams to said lever and to said thrust rod respectively for movement thereby.

2. In a knitting machine as set forth in claim 1, said lever being two-armed, said contact members being mounted on one of the arms of said lever, and said means operatively connecting one of said cams to the other one of said arms.

References Cited in the file of this patent UNITED STATES PATENTS 1,152,850 Scott Sept. 7, 1915 1,282,958 Scott Oct. 29, 1918 7 ,973 Smith et al Mar. 23, 1937 2,387,769 Page et al. Oct. 30, 1945 2,576,962 McDonough Dec. 4, 1951 

